(08-22) 16:34 PDT OAKLAND -- A man who committed suicide by setting himself on fire in Oakland's Fruitvale neighborhood had killed his aunt a month earlier and staged her as the victim of a home-invasion robbery - a scheme he hatched to pay off gambling debts, authorities said Friday.

Richard Fang, 56, was found dead March 1 after firefighters doused a blaze in an alley near an apartment complex on the 1800 block of 37th Avenue. Fang's death was determined to be a suicide.

On Feb. 7, police found the body of Fang's aunt, 77-year-old Susan Fong, inside her apartment at the complex. She died of "probable asphyxiation" due to tape being applied over her nose and mouth, according to the Alameda County coroner's office.

When she was found, police also discovered Fang at the apartment, tied up with his mouth covered with tape. An investigation led police to conclude that Fang, consumed by gambling debts, had made up a story about assailants invading their home and killing Fong, for whom he served as caretaker.

Assistant District Attorney Teresa Drenick said prosecutors were closing the case and were not filing charges because "we determined that the suspect is deceased."